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  <title>Performs a query on the database</title>
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  <div id="layout-content"><div id="function.maxdb-query" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">maxdb_query</h1>
  <h1 class="refname">maxdb::query</h1>
  <p class="verinfo">(PECL maxdb &gt;= 1.0)</p><p class="refpurpose"><span class="refname">maxdb_query</span> -- <span class="refname">maxdb::query</span> &mdash; <span class="dc-title">Performs a query on the database</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-function.maxdb-query-description">
  <h3 class="title">说明</h3>
  <p class="para">过程化风格</p>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>maxdb_query</strong></span>
    ( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$link</code></span>
   , <span class="methodparam"><span class="type">string</span> <code class="parameter">$query</code></span>
   [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$resultmode</code></span>
  ] ) : <span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span></div>

  <p class="para rdfs-comment">面向对象风格</p>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>maxdb::query</strong></span>
    ( <span class="methodparam"><span class="type">string</span> <code class="parameter">$query</code></span>
   ) : <span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span></div>

  <p class="para rdfs-comment">
   The <span class="function"><strong>maxdb_query()</strong></span> function is used to simplify the
   act of performing a query against the database represented by the
   <code class="parameter">link</code> parameter.
  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.maxdb-query-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功时返回 <strong><code>TRUE</code></strong>， 或者在失败时返回 <strong><code>FALSE</code></strong>。 For <em>SELECT, SHOW, DESCRIBE</em> or
   <em>EXPLAIN</em> <span class="function"><strong>maxdb_query()</strong></span> will return
   a result resource.
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.maxdb-query-examples">
  <h3 class="title">范例</h3>
  <div class="example" id="example-1391">
   <p><strong>Example #1 面向对象风格</strong></p>
   <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$maxdb&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">maxdb</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"MONA"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"RED"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"DEMODB"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;connection&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">maxdb_connect_errno</span><span style="color: #007700">())&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect&nbsp;failed:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">maxdb_connect_error</span><span style="color: #007700">());<br />&nbsp;&nbsp;&nbsp;exit();<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;Create&nbsp;table&nbsp;doesn't&nbsp;return&nbsp;a&nbsp;resultset&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">$maxdb</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"CREATE&nbsp;TABLE&nbsp;temp.mycity&nbsp;LIKE&nbsp;hotel.city"</span><span style="color: #007700">)&nbsp;===&nbsp;</span><span style="color: #0000BB">TRUE</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Table&nbsp;mycity&nbsp;successfully&nbsp;created.\n"</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;Select&nbsp;queries&nbsp;return&nbsp;a&nbsp;resultset&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$maxdb</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT&nbsp;name&nbsp;FROM&nbsp;hotel.city"</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Select&nbsp;returned&nbsp;%d&nbsp;rows.\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$result</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">num_rows</span><span style="color: #007700">);<br /><br />&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">/*&nbsp;free&nbsp;result&nbsp;set&nbsp;*/<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$result</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">close</span><span style="color: #007700">();<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;If&nbsp;we&nbsp;have&nbsp;to&nbsp;retrieve&nbsp;large&nbsp;amount&nbsp;of&nbsp;data&nbsp;we&nbsp;use&nbsp;MAXDB_USE_RESULT&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$maxdb</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT&nbsp;*&nbsp;FROM&nbsp;hotel.city"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">MAXDB_USE_RESULT</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$result</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">close</span><span style="color: #007700">();<br />}<br /><br /></span><span style="color: #0000BB">$maxdb</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">close</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
   </div>

  </div>
  <div class="example" id="example-1392">
   <p><strong>Example #2 过程化风格</strong></p>
   <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$link&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">maxdb_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"MONA"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"RED"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"DEMODB"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;connection&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">maxdb_connect_errno</span><span style="color: #007700">())&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect&nbsp;failed:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">maxdb_connect_error</span><span style="color: #007700">());<br />&nbsp;&nbsp;&nbsp;exit();<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;Create&nbsp;table&nbsp;doesn't&nbsp;return&nbsp;a&nbsp;resultset&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">maxdb_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"CREATE&nbsp;TABLE&nbsp;temp.mycity&nbsp;LIKE&nbsp;hotel.city"</span><span style="color: #007700">)&nbsp;===&nbsp;</span><span style="color: #0000BB">TRUE</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Table&nbsp;mycity&nbsp;successfully&nbsp;created.\n"</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;Select&nbsp;queries&nbsp;return&nbsp;a&nbsp;resultset&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">maxdb_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"SELECT&nbsp;name&nbsp;FROM&nbsp;hotel.city"</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Select&nbsp;returned&nbsp;%d&nbsp;rows.\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">maxdb_num_rows</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">));<br /><br />&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">/*&nbsp;free&nbsp;result&nbsp;set&nbsp;*/<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">maxdb_free_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;If&nbsp;we&nbsp;have&nbsp;to&nbsp;retrieve&nbsp;large&nbsp;amount&nbsp;of&nbsp;data&nbsp;we&nbsp;use&nbsp;MAXDB_USE_RESULT&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">maxdb_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"SELECT&nbsp;*&nbsp;FROM&nbsp;hotel.city"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">MAXDB_USE_RESULT</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">maxdb_free_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #0000BB">maxdb_close</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
   </div>

  </div>
  <p class="para">以上例程的输出类似于：</p>
  <div class="example-contents screen">
<div class="cdata"><pre>
Table mycity successfully created.
Select returned 25 rows.
</pre></div>
  </div>
 </div>


 <div class="refsect1 seealso" id="refsect1-function.maxdb-query-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="maxdb_real_query.html" class="function" rel="rdfs-seeAlso">maxdb_real_query()</a> - Execute an SQL query</span></li>
    <li class="member"><span class="function"><a href="maxdb_multi_query.html" class="function" rel="rdfs-seeAlso">maxdb_multi_query()</a> - Performs a query on the database</span></li>
    <li class="member"><span class="function"><a href="maxdb_free_result.html" class="function" rel="rdfs-seeAlso">maxdb_free_result()</a> - Frees the memory associated with a result</span></li>
   </ul>
  </p>
 </div>


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